KEY BISCAYNE, Fla. -

It had been  a long Sunday of partying on the Nixon beach sand bar, off nearBill Baggs Florida State Parkin Key Biscayne

About 7 p.m., a 40-foot boat got stuck on a sandbar, authorities said. No one wanted to wait until high tide at 1:30 a.m., so a group moved to push the boat.

That was when Ernesto Hernandez, 23, of Hialeah, ended up on the back of the vessel. His torso got caught on the boat's moving propeller, Florida Fish and Wildlife Conservation Commission spokesman Jorge Pino said.

"One of the engines actually caught his body," Pino said.

There were dozens of witnesses. Hours before the tragedy, Cuban-American personality Lazaro Mendez, better known as DJ Laz, used social media to promote aVoli Vodkaparty on the Nixon Beach sandbar Sunday. Mendez's friend Pitbull has been promoting the vodka brand heavily.

It was a horrific ending to the Cinco de Mayo celebration Sunday.

Rescue airlifted Hernandez to Jackson Memorial Hospital, where he was pronounced dead.

The circumstances of Hernandez's death are still under investigation. In Florida, it is legal for all boaters to drink on a vessel, except for the driver, and BUI arrests are rare.

In an unrelated incident off the Upper Keys, also involving a propeller. Raymond Shontere, 21, suffered cuts to his left arm on Easter weekend.  He was drunk, lost his balance and fell off the back of the boat, FWC spokesman Robert Dube said.

The One and Only Local 10 News reporter Roger Lohse is investigating.